A VPN won’t protect you from a rogue provider of public WiFi. A malicious WiFi operator could intercept the connection between yourself and the VPN; you’d never know. It’s best to stick with WiFi that you trust or better still use 3G/4G. A VPN does make it harder for unsophisticated attackers to intercept your data.
In addition to trusting the public WiFi operator you must also trust your VPN provider not to do anything nasty like replacing the OneDrive SSL certificates. Assuming that they’re not intercepting your connection to OneDrive then the connection between your computer and OneDrive is safe.
As long as both of the above two criteria are satisfied then you’re safe.
Now you know of the general ways in which your connection may be compromised I’ll explain a bit more –
Because you’re using AxCrypt you enjoy an additional layer of security in that even if a rogue WiFi operator and/or a rogue VPN provider were to intercept your connection, then all they’d see is encrypted data because of the how AxCrypt works.
A very sophisticated attacker may attempt to intercept your connection to AxCrypt servers so if you’re in a high-risk environment you should activate ‘Always Offline’ within AxCrypt prior to connecting to the internet.
For most intents and purposes, unless you’re handling exceptionally confidential information, your current setup is more than secure.